frons(V\. XLIX. fig. 1, /, figs. 2, 2'), with a fuller subelliptic section, have the long axis 

 directed from before more outwardly as it extends backward. The pair of teeth present 

 a broader surface forward ; in Phascolomys platyrhinus they present a broader surface 

 outward, — the surface in both species being the convex enamelled one; the enamel in 

 both, also, is longitudinally striate. A larger proportion of the upper incisor is coated 

 with enamel in Phascolomys platyrhinus (PI. XLVI.1I. fig. 2') than in Phascolomys hdi- 

 frons (PI. XLIX. fig. 2'). Commencing in the former near the hind border, it extends 

 along the outside, over the front border, and along the inner side to a longitudinal 

 indent three fourths of the way toward the hind border. The enamel in Phascolomys 

 latifrons, commencing at the hind border, which is rather the outer one, extends over 

 the fore part and upon the inner surface to where it bends to form the hind surface. 

 The extent of this hind part of the tooth coated only with cement (PI. XLIX. 

 fig. 2', c) is greater in Phascolomys latifrons than is the corresponding uncnamelled 

 tract in Phascolomys platyrhinus. 



The first upper molar in Phascolomys platyrhinus (PI. XLVHI. fig. 1, & fig. 3, <l ..) 

 presents a subtriangular transverse section or working-surface, the base being backward, 

 the apex forward ; the inner side is shorter than the outer side, and is indented near the 

 apex by a groove traversing the tooth lengthwise ; the outer angle of the base is some- 

 times, by oblique attrition, produced. The enamel begins anteriorly at the outer part 

 of the apex (fig. 3, e), opposite the groove, is continued inward and backward, and upon 

 the base two thirds of the way toward the outer angle, which, with the outer side of 

 the tooth to near the anterior angle or apex, is coated only by cement (ib. r). 



In Phascolomys latifrons the worn surface of the first upper molar (PI. XLIX. fig. 1 

 & fig. 3, d 3) is subquadrate ; or, if viewed as triangular, the antero-internal surface 

 forms the base, and the postero-external angle the obtusely truncated apex. There is a 

 feeble indication of a longitudinal groove, representing that in Phascolomys platyrhinus 

 (PI. XLVIII. fig. 3, (j) ; but it does not mark off an anterior production of the tooth 

 in the bare-nosed species, it simply indents the base or shorter side of the triangle. 

 The enamel extends from the base upon the fore and outer part (PI. XLIX. fig 3, e) 

 and upon the hind part of the tooth, leaving about the same extent of the outer and 

 hinder part unenamelled and coated with cement (c) as in Phascolomys platyrhinus. 

 The chief distinction is the deeper antero-internal longitudinal groove (PI. XLVIII. 

 fig. 3, a) marking off a more definite anterior angle or lobule of the grinding-surface 

 of (1 3 in both the bare-nosed Wombats ; by which character a detached tooth might 

 be determined as not belonging to the hairy-nosed species. There is only some dif- 

 ference in size between d 3, upper jaw, of Phascolomys platyrhinus and that of Phasco- 

 lomys vombatus. 



The second molar (d 4) assumes a greater proportional size to the first (d 8) in Phas- 

 colomys platyrhinus than in Phascolomys latifrons; and the succeeding molars repeat the 

 same degree of superiority of size. The longitudinal extent of the upper molar series in 

 Phascolomys platyrhinus averages 2 inches 1 line; in Phascolomys latifrons it averages 



